There is a small compact machine that is called an "AED" which stands for "Auto External Defibrillator". Sells for about $1200.00, and all first responders in my area are trained to use them. You will see them at most public places (malls, etc), and are mounted in a glass type enclosure on the wall.
The machine will give audible instructions when you open it, and tell you exactly what to do, such as, bare the chest, place pad A on upper chest area, and pad B on lower chest area, etc. Then the machine actually takes a reading on the victim and if no pulse is detected, it will tell you to "push the activation button, and stay clear of the victim". It will then "shock" the victim, but only if no pulse is detected. The machine will tell you when to shock again, or continue CPR.
I notice more and more of them at local stores (Wal-Mart),and the staff of the stores are trained (for the most part) on how to use the machine.
Some of the Supervisors that work the road at my Sheriff's Office carry them in their units.
Depending on the time the victim at Club O was submerged, it might not have worked, but it is always worth a chance to try. I have never seen one of the AED machines anywhere on a Cruise Ship, nor anywhere at Club O when we stayed there.
Maybe they are just in the US.